/**

 * jQuery.ScrollTo

 * Copyright (c) 2008 Ariel Flesler - aflesler(at)gmail(dot)com | http://flesler.blogspot.com

 * Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php)

 * and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.

 * Date: 2/19/2008

 *

 * @projectDescription Easy element scrolling using jQuery.

 * Tested with jQuery 1.2.1. On FF 2.0.0.11, IE 6, Opera 9.22 and Safari 3 beta. on Windows.

 *

 * @author Ariel Flesler

 * @version 1.3.3

 *

 * @id jQuery.scrollTo

 * @id jQuery.fn.scrollTo

 * @param {String, Number, DOMElement, jQuery, Object} target Where to scroll the matched elements.

 *	  The different options for target are:

 *		- A number position (will be applied to all axes).

 *		- A string position ('44', '100px', '+=90', etc ) will be applied to all axes

 *		- A jQuery/DOM element ( logically, child of the element to scroll )

 *		- A string selector, that will be relative to the element to scroll ( 'li:eq(2)', etc )

 *		- A hash { top:x, left:y }, x and y can be any kind of number/string like above.

 * @param {Number} duration The OVERALL length of the animation, this argument can be the settings object instead.

 * @param {Object} settings Hash of settings, optional.

 *	 @option {String} axis Which axis must be scrolled, use 'x', 'y', 'xy' or 'yx'.

 *	 @option {Number} duration The OVERALL length of the animation.

 *	 @option {String} easing The easing method for the animation.

 *	 @option {Boolean} margin If true, the margin of the target element will be deducted from the final position.

 *	 @option {Object, Number} offset Add/deduct from the end position. One number for both axes or { top:x, left:y }.

 *	 @option {Object, Number} over Add/deduct the height/width multiplied by 'over', can be { top:x, left:y } when using both axes.

 *	 @option {Boolean} queue If true, and both axis are given, the 2nd axis will only be animated after the first one ends.

 *	 @option {Function} onAfter Function to be called after the scrolling ends. 

 *	 @option {Function} onAfterFirst If queuing is activated, this function will be called after the first scrolling ends.

 * @return {jQuery} Returns the same jQuery object, for chaining.

 *

 * @example $('div').scrollTo( 340 );

 *

 * @example $('div').scrollTo( '+=340px', { axis:'y' } );

 *

 * @example $('div').scrollTo( 'p.paragraph:eq(2)', 500, { easing:'swing', queue:true, axis:'xy' } );

 *

 * @example var second_child = document.getElementById('container').firstChild.nextSibling;

 *			$('#container').scrollTo( second_child, { duration:500, axis:'x', onAfter:function(){

 *				alert('scrolled!!');																   

 *			}});

 *

 * @example $('div').scrollTo( { top: 300, left:'+=200' }, { offset:-20 } );

 *

 * Notes:

 *  - jQuery.scrollTo will make the whole window scroll, it accepts the same arguments as jQuery.fn.scrollTo.

 *	- If you are interested in animated anchor navigation, check http://jquery.com/plugins/project/LocalScroll.

 *	- The options margin, offset and over are ignored, if the target is not a jQuery object or a DOM element.

 *	- The option 'queue' won't be taken into account, if only 1 axis is given.

 */

;(function( $ ){



	var $scrollTo = $.scrollTo = function( target, duration, settings ){

		$scrollTo.window().scrollTo( target, duration, settings );

	};



	$scrollTo.defaults = {

		axis:'y',

		duration:1

	};



	//returns the element that needs to be animated to scroll the window

	$scrollTo.window = function(){

		return $( $.browser.safari ? 'body' : 'html' );

	};



	$.fn.scrollTo = function( target, duration, settings ){

		if( typeof duration == 'object' ){

			settings = duration;

			duration = 0;

		}

		settings = $.extend( {}, $scrollTo.defaults, settings );

		duration = duration || settings.speed || settings.duration;//speed is still recognized for backwards compatibility

		settings.queue = settings.queue && settings.axis.length > 1;//make sure the settings are given right

		if( settings.queue )

			duration /= 2;//let's keep the overall speed, the same.

		settings.offset = both( settings.offset );

		settings.over = both( settings.over );



		return this.each(function(){

			var elem = this, $elem = $(elem),

				t = target, toff, attr = {},

				win = $elem.is('html,body');

			switch( typeof t ){

				case 'number'://will pass the regex

				case 'string':

					if( /^([+-]=)?\d+(px)?$/.test(t) ){

						t = both( t );

						break;//we are done

					}

					t = $(t,this);// relative selector, no break!

				case 'object':

					if( t.is || t.style )//DOM/jQuery

						toff = (t = $(t)).offset();//get the real position of the target 

			}

			$.each( settings.axis.split(''), function( i, axis ){

				var Pos	= axis == 'x' ? 'Left' : 'Top',

					pos = Pos.toLowerCase(),

					key = 'scroll' + Pos,

					act = elem[key],

					Dim = axis == 'x' ? 'Width' : 'Height',

					dim = Dim.toLowerCase();



				if( toff ){//jQuery/DOM

					attr[key] = toff[pos] + ( win ? 0 : act - $elem.offset()[pos] );



					if( settings.margin ){//if it's a dom element, reduce the margin

						attr[key] -= parseInt(t.css('margin'+Pos)) || 0;

						attr[key] -= parseInt(t.css('border'+Pos+'Width')) || 0;

					}



					attr[key] += settings.offset[pos] || 0;//add/deduct the offset



					if( settings.over[pos] )//scroll to a fraction of its width/height

						attr[key] += t[dim]() * settings.over[pos];

				}else

					attr[key] = t[pos];//remove the unnecesary 'px'



				if( /^\d+$/.test(attr[key]) )//number or 'number'

					attr[key] = attr[key] <= 0 ? 0 : Math.min( attr[key], max(Dim) );//check the limits



				if( !i && settings.queue ){//queueing each axis is required					

					if( act != attr[key] )//don't waste time animating, if there's no need.

						animate( settings.onAfterFirst );//intermediate animation

					delete attr[key];//don't animate this axis again in the next iteration.

				}

			});			

			animate( settings.onAfter );			



			function animate( callback ){

				$elem.animate( attr, duration, settings.easing, callback && function(){

					callback.call(this, target);

				});

			};

			function max( Dim ){

				var el = win ? $.browser.opera ? document.body : document.documentElement : elem;

				return el['scroll'+Dim] - el['client'+Dim];

			};

		});

	};



	function both( val ){

		return typeof val == 'object' ? val : { top:val, left:val };

	};



})( jQuery );